Field of the Invention
The present invention relates to a camera and a camera accessory interchangeably attachable to the camera such as an interchangeable lens.
Description of the Related Art
Such camera accessories (each hereinafter simply referred to as “an accessory”) receive, in a state of being attached to a camera, supply of power from the camera and perform communication of commands, data or the like with the camera. In order to perform such supply of power and communication, an attachment portion (mount) of the camera and that of the accessory are provided with multiple electrical contacts (each hereinafter simply referred to as “a contact”) in which paired ones are brought into contact with each other to establish electrical connection. Moreover, as a method of the attachment (coupling) of the camera and the accessory, bayonet coupling is often used in which the mounts of the camera and accessory are relatively rotated to cause bayonet claws provided in the respective mounts to engage with each other.
Japanese Patent Laid-Open No. 62-195633 discloses a camera and an interchangeable lens as an accessory respectively having a camera side mount and a lens side mount that are coupled with each other by the bayonet coupling method. In a coupling completion state after relative rotation of the camera side and lens side mounts, each of multiple camera side electrical contact pins provided in the camera side mount makes contact with corresponding each of multiple lens side electrical contact pins provided in the lens side mount. The camera side and lens side electrical contact pins are respectively held by camera side and lens side contact bases provided in the camera side and lens side mounts. The camera side contact base is provided with hole portions into which the camera side electrical contact pins are inserted to be held thereby, and each camera side electrical contact pin is biased in a direction (protruding direction) of protruding from the hole portion by a spring disposed between the camera side electrical contact pin and a printed wiring board placed at bottom of the hole portion. The lens side electrical contact surfaces (pins) are fixedly held by the lens side contact base.
Moreover, in the camera disclosed in Japanese Patent Laid-Open No. 62-195633, some of the multiple camera side electrical contact pins are disposed at a position (that is, a convex step) protruded toward the interchangeable lens further than the other camera side electrical contact pins. Hereinafter, “the other camera side electrical contact pins” are referred to as “first camera side contact pins”, and “the some camera side electrical contact pins” are referred to as “second camera side contact pins”. Furthermore, in the camera disclosed in Japanese Patent Laid-Open No. 62-195633, of the multiple lens side electrical contact surfaces, second lens side contact surfaces to make contact with the second camera side contact pins are disposed at a position recessed on an opposite side to the camera further than first lens side contact surfaces to make contact with the first camera side contact pins. The second camera side contact pins and the second lens side contact surfaces make contact with one another at end or immediately therebefore during the relative rotation of the camera and interchangeable lens in a direction (coupling direction) toward the coupling completion state. This configuration reduces a number of times at which the first and second camera side contact pins are scraped against the first and second lens side contact surfaces during the relative rotation of the camera and interchangeable lens in the coupling direction (and in a detaching direction), thereby suppressing wear of the camera side contact pins.
However, the camera and interchangeable lens disclosed in Japanese Patent Laid-Open No. 62-195633 first causes, before the relative rotation in the coupling direction, their mounts to make contact with each other in a direction (optical axis direction) in which a central axis of their relative rotation extends. At the time of the contact of the mounts, hard contact (hit) of the lens side contact base including the lens side contact surfaces to the first camera side contact pin might cause tilt of the first camera side contact pin from its original position or deformation (such as bending) thereof. Such tilt or deformation makes the first camera side contact pin unable to make contact with the corresponding first lens side contact surface, or causes the first camera side contact pin to make contact with another first lens side contact surface adjacent to the corresponding lens side contact surface, which prevents securement of normal (correct) electrical connection and thereby causes communication error between the camera and the interchangeable lens, operation failure of the camera or the interchangeable lens due to power source short-circuiting or the like.